Several email applications have support for sending and receiving encrypted messages. In order to make this guide more simple, though, we will focus on using Mozilla Thunderbird since it works on macOS, Ubuntu, and Windows. The process should, however, be similar using other applications.

Install Thunderbird email client

Set up your email account

The first time you open Thunderbird, you will automatically be guided through the process of setting up your email account. In most cases, all you have to do is enter your email account and password and it will begin working.

Install the Enigmail add-on

In order to encrypt and decrypt emails in Thunderbird, you'll need to install the Enigmail add-on.

Windows and Ubuntu
In Thunderbird, click on the hamburger icon (represented by three horizontal lines) in the top right-hand corner and select add-ons. If you don't see a search bar in the next window, click on Extensions in the left-hand menu. In the search bar, type in "Enigmail" and hit Enter.

In the list of results, find Enigmail and click the Install button. Once installed, you will be prompted to restart Thunderbird.

macOS
In Thunderbird, navigate to Menu, Tools, Add-ons.

Scroll down to the Featured Add-ons section and select "Enigmail" to add it to Thunderbird. Once installed, you will be prompted to restart Thunderbird.

Set up Enigmail

After Thunderbird has restarted, a guide for setting up Enigmail will automatically begin.

Choose the standard setup. Enigmail will automatically detect your key since you already installed GnuPG (as outlined in our guide on the basics of encryption). Select your key and your setup is complete!

Send and receive encrypted emails

When someone sends you their public key as an email attachment, right click on the attached file and select "Import OpenPGP Key."

When you compose a new email, you will see an unlocked lock in the toolbar. Click on this icon in order to encrypt the email with the recipient's public key. You will also see an option for attaching your public key to an email.